Hmm. The alpha should still work on most Windows machines (older versions of Game Maker stuff tends to rot as OSes update) I would recommend checking up on your graphics drivers, some have had issues with GM games, doing a full removal of your current drivers and installing the most recent ones should help... Otherwise I have to always ask if you've fully extracted the game before running it - some people run the game from inside the zip and that causes a lot of issues.

<sigh>Sorry for the late reply to this, but after some fiddling around I found the very basic error made by me was that I hadn't updated my display drivers. Not something I realised was out of date, but a quick update/reboot and this resolved the problem.

Thanks for the response, and apologies for not spotting this myself sooner!